valve springs

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06-22-2012, 06:04 AM

#11

oatburner99

2nd Gear Member

Join Date: Feb 2010

Location: Texas

Posts: 303

Quote:

Originally Posted by van-swink85

Ok just found out that mine are 1.7s with my gt40 heads so does that mean i will encounter th same problem as you did? And another question is i was told i would have to have something else because i was putting a windsor style head on a 302?

Gt40 heads came from the factory with 1.7's (Crane/Ford) You may or may not, it depends on your shim stack for your springs, and setting up your rocker lash. You wont know until you measure.

Quote:

Originally Posted by van-swink85

Like a bushing or something that goes from a 1/2 to a 7/16...ever heard of anything like that?

What they are talking about is, the GT40 head bolt BORE is 1/2 (i.e the bolts are half inch. The holes in the block are 7/16 (smaller) Well obviously you can't use 1/2 bolts in a 7/16 hole in the block, so you have to use 7/16 size bolts. Well the inner diameter for the heads is BIGGER (1/2) so it won't be a close tolerance fit. What you can do is pick these up:
http://www.latemodelrestoration.com/...ngs-Pack-Of-20

06-22-2012, 06:45 AM

#12

van-swink85

1st Gear Member

Thread Starter

Join Date: Oct 2009

Location: alabama

Posts: 98

Awesome guys cant thank you all enough for the help

06-22-2012, 11:20 PM

#13

projectresto83

M.A.D. Motorsports

Join Date: Jul 2006

Location: Indiana

Posts: 8,014

Quote:

For what it's worth, I have an e cam in my car, with gt40's and ran a set of springs from Alex Parts, which are good up to .600' worth of lift. I initially put 1.7's on there, (which was .598 worth of lift) but the bolts were bottoming out in the head, so I went back to the 1.6's. They have a better lift and seat pressure capability than the trick flow's. Not only that, but you can't beat the price:
http://www.alexsparts.com/sb-ford-gt...it-hyd-roller/
I've got around 1500 miles on my setup so far, and have ran the car all the way to 6800 rpm and it still pulls. Hope this helps.

Hey E...... 1.7's will put the E cam at .529 lift...not .598...

OP, for the bolt issue...use the correct length bolt and there won't be an issue. Not all GT40's have a 7/16 head bolt size. Some are 1/2" as well as some have already said. Oat has given the link to the bushings that work well for the 1/2" heads. If you are curious why there are 2 different sizes its because the GT40's were also used on the mid 90's lightnings...which were 351W...which use 1/2" head bolts.